Enable And Disable Iscsi Optimization; Synchronizing Iscsi Sessions Learned On Vlt-Lags With Vlt-Peer; Monitoring Iscsi Traffic Flows - Dell Z9500 Configuration Manual

Up Time:00:00:01:28(DD:HH:MM:SS)
Time for aging out:00:00:09:34(DD:HH:MM:SS)
ISID:806978696102
Initiator Initiator
IP Address TCP Port
10.10.0.53 33432

Enable and Disable iSCSI Optimization

The following describes enabling and disabling iSCSI optimizaiton.
NOTE: iSCSI monitoring, auto-configuration and auto-detection is enabled by default.
If you enable iSCSI, flow control is automatically enabled on all interfaces. To disable flow control on all interfaces, use the no
flow control rx on tx off command and save the configuration. To disable iSCSI optimization, which can turn on flow
control again on reboot, use the no iscsi enable command and save the configuration.
When you enable iSCSI on the switch, the following actions occur:
• Link-level flow control is enabled on interfaces where PFC is disabled.
• iSCSI session snooping is enabled.
• iSCSI LLDP monitoring starts to automatically detect EqualLogic arrays.
The following message displays when you enable iSCSI on a switch and describes the configuration changes that are
automatically performed:
%SYSTEM:CP %IFMGR-5-IFM_ISCSI_ENABLE: iSCSI has been enabled causing flow control to be enabled
on all interfaces. EQL detection and enabling iscsi profile-compellent on an interface may
cause some automatic configurations to
occur like jumbo frames on all ports and no storm control and spanning tree port-fast on the
port of detection.
You can reconfigure any of the auto-provisioned configuration settings that result when you enable iSCSI on a switch.
When you disable the iSCSI feature, iSCSI resources are released and the detection of EqualLogic arrays using LLDP is disabled.
Disabling iSCSI does not remove the MTU, flow control, portfast, or storm control configuration applied as a result of enabling
iSCSI.
NOTE: By default, CAM allocation for iSCSI is set to 0. This disables session monitoring.
Synchronizing iSCSI Sessions Learned on VLT-Lags
with VLT-Peer
The following behavior occurs during synchronization of iSCSI sessions.
• If the iSCSI login request packet is received on a port belonging to a VLT lag, the information is synced to the VLT peer and
the connection is associated with this interface.
• Additional updates to connections (including aging updates) that are learnt on VLT lag members are synced to the peer.
• When receiving an iSCSI login request on a non-VLT interface followed by a response from a VLT interface, the session is
not synced since it is initially learnt on a non-VLT interface through the request packet.
• The peer that sees the login response packet generates a new connection log. If the login response packet uses the ICL
path, it is seen by both the peers, which in turn generate logs for this connection.

Monitoring iSCSI Traffic Flows

The switch snoops iSCSI session-establishment and termination packets by installing classifier rules that trap iSCSI protocol
packets to the CPU for examination.
Devices that initiate iSCSI sessions usually use well-known TCP ports 3260 or 860 to contact targets. When you enable iSCSI
optimization, by default the switch identifies IP packets to or from these ports as iSCSI traffic.
Target Target
IP Address TCPPort
10.10.0.101 3260
Connection
ID
0
iSCSI Optimization 456